Computed List of Emission and Recombination Coefficients for O II Recombination Lines

The list presents emission and recombination coefficients of the O II transitions arising from recombination of doubly-ionised oxygen O^{2+} with a free electron. An intermediate coupling treatment that fully accounts for the dependence of the distribution of population among the ground levels of O^{2+} on electron temperature (T_e) and electron number density (N_e) is used. The calculation is extended down to low electron temperatures where dielectronic recombination arising from Rydberg states converging on the O^{2+} ground levels is an important process. The data are given as function of T_e and N_e in three Cases (A, B and C). The data are suitable in particular for the physical conditions found in planetary nebulae and H II regions. An interactive data server in the form of fortran 77 code is also provided as an accessory for mining the data of emission coefficients and obtaining Lagrange interpolated values for any choice of the two variables, T_e and N_e, between the explicitly provided values for any set of wavelengths and for any Case.

本数据集收录了双电离氧（doubly-ionised oxygen, O²+）与自由电子复合过程所产生的氧II（O II）跃迁的发射系数与复合系数。本研究采用中间耦合处理方案，充分考虑了O²+基态能级的布居分布随电子温度（electron temperature, T_e）与电子数密度（electron number density, N_e）的变化关系。计算范围延伸至低电子温度区间，此时以收敛于O²+基态能级的里德伯态（Rydberg states）为来源的双电子复合（dielectronic recombination）是不可忽视的关键物理过程。数据以T_e和N_e为自变量，分为A、B、C三种情况给出。该数据集尤其适配行星状星云（planetary nebulae）与H II区的物理环境条件。此外还附带了一套Fortran 77代码实现的交互式数据服务器，可用于提取发射系数数据，并针对任意波长组合与任意情况，在已明确提供的T_e和N_e取值范围内，对这两个变量进行任意取值的拉格朗日插值（Lagrange interpolation）计算。